72 



COPEPODA 



14. Spinocalanus magnus Wolf. 



1904. Spinocalanus magnus n. sp. Wolfenden, p. 118. 1 190S. Spinocalanus magnus Wolf. Farran, p. 27. 



1905. — — Wolf. Farran, pp. 30—31, pi. IV 190S. — — — v. Bremen, p. 29, fig. 29. 



figs. I — 12. 



1906. — — — Pearson, pp. 10— 11. 



1907. — — — Damas & Koefoed, p. 409. 



1911? — — — Wolfenden, pp. 216-217, 



text-f. S, pi. XXV figs. 3—5. 



Description, f?. Size of female from Thor St. 82 2*8 mm.; anterior division measured 2"2; nro- 

 some 0-6 mm. Wolfenden's specimens measured 275 and Farran's 2-9 mm. 



As far as could be made oiit by the examination of the two very mutilated specimens, they 

 do not seem to differ in any feature of interest from Farran's description. 



In the second pair of legs no glandular pores were observed in the first outer segment, but a 

 distinct one in the second segment, and three near the base of Se in the third outer segment. 



In front of the labrum proper, which is very prominent, a smoothly rounded elevation was 

 found; the structure of the labrum etc. was not examined in detail. 



Occurrence. Of this species I have only examined two mutilated females, gathered by the 

 Thor M/(, 1905 St. 82 5i°oo L. N. 11^43 L. W. Yt. 1200 M. Wire. 



Distribution. This species is according to Farran of frequent occurrence on the west coast 

 of Ireland "from the surface to i-ooo fathoms, though never very plentiful". According to Koefoed 

 & Damas it is found "dans la raer dn Gronland: de 800 a an moins i-8oo metres". According to the 

 tables prepared by Koefoed, it has been found at four stations, but according to the records from 

 each single station it has only been found at St. 22 79° L. N. i°52 h. E. 800—1350 metres and at St. 48 

 71° L. N. i8°58 L,. W. 800—1000 metres. The .species is by Wolfenden recorded from the Antarctic, 

 but he is probably not right in referring the Antarctic animals to the northern species, as his figure 

 shows the genital somite less distinctly produced. 



Aetideidae G. O. Sars. 



Little by little a good manj- genera of the Aetideidae hav'e been established; these genera are not 

 at all of equal value, and in their definition not the same principles have been followed. M)- material 

 has not been sufficienth' exhaustive for a final solution of the question, but nevertheless a few remarks 

 upon the value and the position of the genera, which I have examined, may be useful. 



As a whole I think that undue stress has been placed on the presence or absence of the 

 lanielli-formed setae or spines along the inner margin of second basipodite in the fourth pair of legs. 

 Cliiridius and Aefidiopsis are the only genera in which marginal setae of usual structure without 

 spines are found; in Aetidius (PI. II fig. ic) terminally and posteriorly a few teeth were found in 

 addition to the usual slender setae. In most species of Gaiditis, Gaetamis and Eucliirella the setae are 

 transformed into more or less well developed spines. In Underchate minor and nearly related species 

 the margin is either completely smooth or possessses a few terminal teeth (cf. text-figure) and in Chiru- 

 dina^ the margin is either completely smooth as in Cli. Streetsi, or possesses well developed spines 



